Evaluation of the antidepressant- and anxiolytic-like effects of a hydrophilic extract from the green seaweed Ulva sp. in rats

Unlocking the potential of edible Ulva sp. seaweeds: Metabolomic profiling, neuroprotective mechanisms, and implications for Parkinson's disease management

Green seaweed (Ulva sp.) is frequently used as a food component and nutraceutical agent because of its high polysaccharide and natural fiber content in Asian countries. This study investigates both metabolomic profiling of Ulva sp. and the neuroprotective efficacy of its ethanol extract and its underlying mechanisms in a rotenone-induced rat model of neurodegeneration, mimicking Parkinson's disease (PD) in humans. Metabolomic profiling of Ulva sp. extract was done using liquid chromatography high resolution electrospray ionization mass spectrometry and led to the identification of 22 compounds belonging to different chemical classes.Catenin Beta Additionally, this study demonstrated the neuroprotective properties against rotenone-induced PD, which was achieved through the suppression of elevated levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6 together with the inhibition of reactive oxygen species (ROS) generation, apoptosis, inflammatory mediators, and the phosphoinositide 3-kinases/serine/threonine protein kinase (PI3K/AKT) pathway. Using a protein-protein interaction network, AKT1, GAPDH, TNF-α, IL-6, caspase 3, signal transducer and activator of transcription 3, Catenin Beta 1, epidermal growth factor receptor, B-cell lymphoma -2, and HSP90AA1 were identified as the top 10 most significant genes. Finally, molecular docking results showed that compounds 1, 3, and 7 might possess a promising anti-parkinsonism effect by binding to active sites of selected hub genes. Therefore, it is hypothesized that the Ulva sp. extract has the potential to be further developed as a potential therapeutic agent for the treatment of PD.

Marine natural products: potential agents for depression treatment

Depression is a common psychiatric disorder. Due to the disadvantages of current clinical drugs, including poor efficacy and unnecessary side effects, research has shifted to novel natural products with minimal or no adverse effects as therapeutic alternatives. The ocean is a vast ecological home, with a wide variety of organisms that can produce a large number of natural products with unique structures, some of which have neuroprotective effects and are a valuable source for the development of new drugs for depression. In this review, we analyzed preclinical and clinical studies of natural products derived from marine organisms with antidepressant potential, including the effects on the pathophysiology of depression, and the underlying mechanisms of these effects. It is expected to provide a reference for the development of new antidepressant drugs.

Understanding the Role of Oxidative Stress, Neuroinflammation and Abnormal Myelination in Excessive Aggression Associated with Depression: Recent Input from Mechanistic Studies

Aggression and deficient cognitive control problems are widespread in psychiatric disorders, including major depressive disorder (MDD). These abnormalities are known to contribute significantly to the accompanying functional impairment and the global burden of disease. Progress in the development of targeted treatments of excessive aggression and accompanying symptoms has been limited, and there exists a major unmet need to develop more efficacious treatments for depressed patients. Due to the complex nature and the clinical heterogeneity of MDD and the lack of precise knowledge regarding its pathophysiology, effective management is challenging. Nonetheless, the aetiology and pathophysiology of MDD has been the subject of extensive research and there is a vast body of the latest literature that points to new mechanisms for this disorder. Here, we overview the key mechanisms, which include neuroinflammation, oxidative stress, insulin receptor signalling and abnormal myelination. We discuss the hypotheses that have been proposed to unify these processes, as many of these pathways are integrated for the neurobiology of MDD. We also describe the current translational approaches in modelling depression, including the recent advances in stress models of MDD, and emerging novel therapies, including novel approaches to management of excessive aggression, such as anti-diabetic drugs, antioxidant treatment and herbal compositions.

Multi-Step Subcritical Water Extracts of Fucus vesiculosus L. and Codium tomentosum Stackhouse: Composition, Health-Benefits and Safety

Mental health and active aging are two of the main concerns in the 21st century. To search for new neuroprotective compounds, extracts of Codium tomentosum Stackhouse and Fucus vesiculosus L. were obtained through multi-step (four step) subcritical water extraction using a temperature gradient. The safety assessment of the extracts was performed by screening pharmaceutical compounds and pesticides by UHPLC-MS/MS, and iodine and arsenic levels by ICP-MS. Although the extracts were free of pharmaceutical compounds and pesticides, the presence of arsenic and high iodine contents were found in the first two extraction steps. Thus, the health-benefits were only evaluated for the fractions obtained in steps 3 and 4 from the extraction process. These fractions were tested against five brain enzymes implicated in Alzheimer’s, Parkinson’s, and major depression etiology as well as against reactive oxygen and nitrogen species, having been observed a strong enzyme inhibition and radical scavenging activities for the step 4 fractions from both seaweed species. Regarding the variation of the chemical composition during the extraction, step 1 fractions were the richest in phenolic compounds. With the increase in temperature, Maillard reaction, caramelization and thermo-oxidation occurred, and the resulting products positively affected the antioxidant capacity and the neuroprotective effects.

Ultrasound stress compromises the correlates of emotional-like states and brain AMPAR expression in mice: effects of antioxidant and anti-inflammatory herbal treatment

The modern lifestyle is associated with exposure to "psychological" or "emotional" stress. A growing portion of the population is exposed to emotional stress that results in a high incidence of anxiety disorders, a serious social problem. With this rise, there is a need for understanding the neurobiological causes of stress-induced anxiety and to offer safe remedies for this condition. Side effects of existing pharmaceuticals necessitate the search for alternatives. Having fewer adverse effects than classic remedies, natural extract-based therapies can be a promising solution. Here, we applied a model of emotional stress in BALB/c mice using ultrasound exposure to evoke the signs of anxiety-like behavior. We examined the behavioral and molecular impact of ultrasound and administration of herbal antioxidant/anti-inflammatory treatment (HAT) on AMPA receptor expression, markers of plasticity, inflammation and oxidative stress. A 3-week ultrasound exposure increased scores of anxiety-like behaviors in the standard tests and altered hippocampal expression as well as internalization of AMPA receptor subunits GluA1-A3. Concomitant treatment with HAT has prevented increases of anxiety-like behaviors and other behavioral changes, normalized hippocampal malondialdehyde content, GSK3β and pro-inflammatory cytokines Il-1β and Il-6, and the number of Ki67-positive cells. Levels of malondialdehyde, a common measure of oxidative stress, significantly correlated with the investigated end-points in stressed, but not in non-stressed animals. Our results emphasize the role of oxidative stress in neurobiological abnormalities associated with experimentally induced condition mimicking emotional stress in rodents and highlight the potential therapeutic use of anti-oxidants like herbal compositions for management of stress-related emotional disturbances within the community.

Edible seaweed-derived constituents: an undisclosed source of neuroprotective compounds

Edible marine algae, or seaweeds, are a rich source of several bioactive compounds including phytosterols, carotenoids, and polysaccharides. Over the last decades, seaweed-derived constituents turned out to not only reside in the systemic circulation, but are able to cross the blood-brain barrier to exert neuro-active functions both in homeostatic and pathological conditions. Therefore, seaweed-derived constituents have gained increasing interest for their neuro-immunomodulatory and neuroprotective properties, rendering them interesting candidates for the management of several neurodegenerative disorders. In particular seaweed-derived phytosterols gained interest for the treatment of neurodegenerative disorders as they potentiate neuroplasticity, enhance phagocytic clearance of neurotoxic peptides and have anti-inflammatory properties. Though, the anti-inflammatory and anti-oxidative properties of other constituents including carotenoids, phenols and polysaccharides have recently gained more interest. In this review, we provide an overview of a selection of the described neuro-active properties of seaweed-derived constituents with a focus on phytosterols.

Preliminary investigation of the effect of oral supplementation of Lactobacillus plantarum strain SNK12 on mRNA levels of neurotrophic factors and GABA receptors in the hippocampus of mice under stress-free and sub-chronic mild social defeat-stressing conditions

The effect of Lactobacillus plantarum SNK12 (CPLP) supplementation on mRNA levels of hippocampal neurotrophic factors and gamma aminobutyric acid receptors (GABA_R) was tested. In Experiment 1, stress-free, unsupplemented and CPLP (4 × 10⁸ cells/head)-supplemented male C57BL/6J (B6) mice were the experimental animals. In Experiment 2, intruder (male, B6) mice [negative control; unsupplemented, sub-chronic mild social defeat stress (sCSDS)-induced; and CPLP-supplemented, sCSDS-induced] were exposed to aggressor mice (adult male Slc:ICR). mRNA levels of neurotrophic factors and GABA_R in hippocampal samples of these mice were analyzed. In CPLP-supplemented mice of both experiments, mRNA levels of bdnf, nt-3, and GABA_R were upregulated. Moreover, a tendency toward the improvement of habituation ability (Experiment 1) and behavior (Experiment 2) was observed in mice, which may be associated with upregulated neurotrophic factors and GABA_R. We demonstrated that oral supplementation of CPLP to stress-free and stress-induced mice upregulated mRNA levels of hippocampal neurotrophic factors and GABA_R.

Deciphering the anti-Parkinson’s activity of sulphated polysaccharides from Chlamydomonas reinhardtii on the α-Synuclein mutants A30P, A53T, E46K, E57K and E35K

Parkinsonism-linked mutations in alanine and glutamic acid residues of the pre-synaptic protein α-Synuclein (α-Syn) affect specific tertiary interactions essential for stability of the native state and make it prone to more aggregation. Many of the currently available drugs used for the treatment of Parkinson’s disease (PD) are not very effective and are associated with multiple side effects. Recently, marine algae have been reported to have sulphated polysaccharides which offers multiple pharmaceutical properties. With this background, we have isolated sulphated polysaccharides from Chlamydomonas reinhardtii (Cr-SPs) and investigated their effects on inhibition of fibrillation/aggregation of α-Syn mutants through a combination of spectroscopic and microscopic techniques. The kinetics of α-Syn fibrillation establishes that Cr-SPs are very effective in inhibiting fibrillation of α-Syn mutants. The morphological changes associated with the fibrillation/aggregation process have been monitored by transmission electron microscopy. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis gel image suggests that Cr-SPs increase the amount of soluble protein after completion of the fibrillation/aggregation process. The circular dichroism results showed that Cr-SPs efficiently delay the conversion of native protein into β-sheet-rich structures. Thus, the current work has considerable therapeutic implications towards deciphering the potential of Cr-SPs to act against PD and other protein aggregation-related disorders.

Ulva lactuca, A Source of Troubles and Potential Riches

Ulva lactuca is a green macro alga involved in devastating green tides observed worldwide. These green tides or blooms are a consequence of human activities. Ulva blooms occur mainly in shallow waters and the decomposition of this alga can produce dangerous vapors. Ulva lactuca is a species usually resembling lettuce, but genetic analyses demonstrated that other green algae with tubular phenotypes were U. lactuca clades although previously described as different species or even genera. The capacity for U. lactuca to adopt different phenotypes can be due to environment parameters, such as the degree of water salinity or symbiosis with bacteria. No efficient ways have been discovered to control these green tides, but the Mediterranean seas appear to be protected from blooms, which disappear rapidly in springtime. Ulva contains commercially valuable components, such as bioactive compounds, food or biofuel. The biomass due to this alga collected on beaches every year is beginning to be valorized to produce valuable compounds. This review describes different processes and strategies developed to extract these different valuable components.

A randomized controlled double-blind clinical trial comparing versus placebo the effect of an edible algal extract (Ulva Lactuca) on the component of depression in healthy volunteers with anhedonia

BACKGROUND

The effects of the seaweed extract were evaluated on the animal model equivalent of depression compared with a control group treated with the carrier (spring water) and a reference group treated with Imipramine and showed significative effect. This clinical trial was intended to confirm in humans the potential efficacy identified in animals. The primary objective was to compare against a placebo the effect of Ulva L.L extract in healthy volunteers whose anhedonia was characterized by a component of depression.

METHODS

Single-centre double-blind randomized placebo-controlled clinical trial on parallel arms of two groups of 45 subjects. The study could include men or women aged 18 to 65 years with anhedonia characterized by a Snaith Hamilton Pleasure Scale score (SHAPS) of ≥5 and feeling low morale for at least four weeks characterized by a component of depression evaluated on the Quick Inventory of Depressive Symptomatology - Self Report (QIDS-SR). Evaluation criteria: QIDS-SR; Patient Global Improvement Impression (PGII) and Clinical Global Improvement Impression (CGII).

RESULTS

86 subjects were included in the trial: 42 in the placebo group and 44 Ulva group. At D84, QIDS-SR significantly decreased more in the Ulva.L.L. group than in the placebo group (p: 0.0389). This difference is essentially linked to an improvement of the sleep disorders (p: 0.0219), of the psychomotor consequences (p: 0.002) and of the nutrition behaviour (p: 0.0694). 90.1% have the feeling of being improved in the Ulva group vs 72.5% in the placebo group (p: 0.0114) and in parallel 90.9% of the practitioners have the feeling that the subject has improved vs 70.8% (p: 0.0214).

CONCLUSION

This double-blind randomized placebo-controlled trial shows that daily intake for three months of a water-soluble extract of Ulva L.L. continues to significantly improve the component of depression of subjects presenting anhedonia compared with a placebo.

TRIAL REGISTRATION

Trial retrospectively registred on ClinicalTrial.gov under ID: NCT03545399 Date: 05/22/2018.

Investigation of the synergistic effects of haloperidol combined with Calculus Bovis Sativus in treating MK-801-induced schizophrenia in rats

Clinical studies that focused on treating schizophrenia showed that Calculus Bovis Sativus (CBS), a substitute of Calculus Bovis, when used in combination with haloperidol could significantly lower the dosage of haloperidol compared with treatment with haloperidol alone, whereas efficacy was maintained. The aim of this study was to investigate the synergetic anti-schizophrenia effects in rats using CBS in combination with haloperidol. An open field test was conducted to verify the pharmacodynamic effects of a combination treatment of CBS and haloperidol on MK-801-induced schizophrenic rats. Rat plasma concentrations of intragastric haloperidol and intravenous haloperidol were determined after oral administration of a single dose or 1-week of pretreatment with CBS (50 mg/kg). The pharmacodynamic data showed a significant decrease in locomotor activity and an increase in the percentage of the central distance when haloperidol was concomitantly administered with CBS compared with haloperidol administration alone. The AUC0-∞ and Cmax of haloperidol in the orally coadministered groups were significantly higher compared with the oral treatment with haloperidol alone. In conclusion, oral coadministration of CBS with haloperidol resulted in a synergistic effect in rats. The enhanced oral bioavailability of haloperidol when combined with CBS might be attributed to the interaction between them.

Camellia euphlebia exerts its antidepressant-like effect via modulation of the hypothalamic-pituitary-adrenal axis and brain monoaminergic systems

Camellia euphlebia (family, Theaceae) is a Chinese folk medicine, known for its multiple pharmacological properties. The present study aimed to provide further insights into the therapeutic basis of C. euphlebia using several animal behavioral tests and physiological indexes. Tail suspension test, forced swimming test, open-field test, chronic unpredictable mild stress (CUMS), reversal of reserpine-induced hypothermia and palpebral ptosis, and 5-hydroxytryptophane-induced head-twitch response were used to evaluate the antidepressant effect of aqueous extract of Camellia euphlebia (AEC) on mice. The possible underlying mechanism was explored by investigating the changes associated with several parameters of animal behavior, as well as the changes in monoamine neurotransmitter and stress hormone levels in these animals during the tests. Mice administered AEC at 100 and 200 mg/kg/day doses for 7 days showed significantly reduced immobility duration in forced swimming test and tail suspension test, whilst exhibiting no apparent changes in locomotor activity. Additionally, administration of AEC also effectively antagonized reserpine-induced palpebral ptosis and hypothermia and enhanced 5-hydroxytryptophane-induced head-twitch response. AEC significantly elevated the levels of serotonin, noradrenaline and dopamine in the blood and brain compared to non-treated mice. After 28 days of administration, the maximum AEC dose (100 mg/kg/day) significantly reversed CUMS-induced inhibition of weight gain and sucrose intake, while decreasing the levels of plasma adrenocorticotropic hormone and serum corticosterone. The antidepressant effect of AEC appeared to involve the alteration of hypothalamic-pituitary-adrenal axis and monoaminergic systems.